scholarly journals EPOXY POLYMERS BASED ON DIGLYCIDYL ETHERS WITH CYCLIC GROUPS

World Science ◽  
2020 ◽  
Author(s):  
Givi Papava ◽  
Nora Dokhturishvili ◽  
Marina Gurgenishvili ◽  
Ia Chitrekashvili ◽  
Zurab Chubinishvili
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Considerable Increase ◽  
Chemical Nature ◽  
Cyclic Groups ◽  
Epoxy Polymers ◽  
Glycidyl Ethers ◽  
Derivatives Of ◽  
Methyltetrahydrophthalic Anhydride

Glycidyl ethers of polycyclic bisphenols of norbornan type and their phenyl substituted derivatives were obtained and studied. They were solidified by diaminodiphenylsulphon and methyltetrahydrophthalic anhydride. The data of the termogravimetric analysis of the obtained polymers showed that they are characterizes by high thermal – and heat stability.The properties of polymers depend on the structure of the hardener and its chemical nature as well. The properties of polymers were sharply changed when glycidyl derivatives of bisphenols were cured by hardeners of different chemical structure. The presence of cyclic structures in the hardener molecule causes considerable increase of their thermal stability. Polymers on the basis of chlorine substituted glycidyl ethers of polycyclic bisphenols are characterized by incombustibility.

scholarly journals CURING OF DIGLYCIDAL ESTERS OF BISPHENOLS WITH ACID HARDENERS

World Science ◽  
2021 ◽  
Author(s):  
Givi Papava ◽  
Nora Dokhturishvili ◽  
Nazi Gelashvili ◽  
Ia Chtrekashvili ◽  
Ketevan Papava ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Heat Resistance ◽  
Chemical Structure ◽  
Modern Technology ◽  
Temperature Range ◽  
Epoxy Polymers

The unique properties of epoxy polymers have led to their wide application in various fields of modern technology. The influence of the structure of bisphenols on the properties of epoxy polymers, especially thermal ones, is known. However, the chemical structure of the hardener also affects the properties of cured epoxy polymers. As hardeners, we used acid hardeners of various structures: anhydrides of maleic, phthalic, pyromellite, methyltetrahydrophthalic and other acids. The following hardeners give high results in heat resistance: pyromellite and methyltetrahydrophthalic anhydrides. Polymers obtained by curing with these hardeners are deformed in the temperature range of 220-245°C. The use of these hardeners gives high results in terms of thermal stability. These polymers are formed by curing these components. It is known that the properties of epoxy polymers depend on the chemical structure of the glycide ether. There was some interest in investigating the influence on the properties of epoxy polymers as a chemical structure, as well as the nature of hardeners. For this purpose, diglycidal esters based on bisphenols were synthesized.

Synthesis and properties of phthalonitrile-based resins containing spirocycle acetal

2020 ◽  
pp. 095400832097759
Author(s):  
Ke Li ◽  
Hua Yin ◽  
Kun Yang ◽  
Pei Dai ◽  
Ling Han ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Room Temperature ◽  
Laser Desorption Ionization ◽  
Scanning Calorimetry ◽  
Rheological Analysis ◽  
Ionization Time ◽  
Dynamic Mechanical ◽  
Nmr Spectrometry ◽  
Current Context

Designing novel low-melting, high-rigidity phthalonitrile resin is of great significance in the current context of development. In this study, rigid spirocycle acetal structure was introduced into phthalonitrile to reduce the melting point and maintain their thermal stability. The chemical structure of resins was confirmed by nuclear magnetic resonance (NMR) spectrometry, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and Fourier-transform infrared (FTIR) spectroscopy. The curing behaviors were studied by differential scanning calorimetry (DSC). Thermal stability and mechanical properties of the cured resins were investigated by dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The processability was studied by rheological analysis. The results indicated the three monomers had a low melting temperature, wide processing windows and low viscosities. These polymers did not exhibit Tg from room temperature to 400°C, exhibited superb dynamic mechanical property and thermal stability.

On the influence of the chemical structure of polymers on their thermal stability

1981 ◽  
Vol 23 (9) ◽  
pp. 2194-2208 ◽  
Author(s):  
Yu.I. Matveyev ◽  
A.A. Askadskii ◽  
I.V. Zhuravleva ◽  
G.L. Slonimskii ◽  
V.V. Korshak
Keyword(s):  
Thermal Stability ◽  
Chemical Structure

Preparation and Pyrolysis of Stereoisomeric Bromobicyclo[n.1.0]alkanes ( n = 6, 8 , 10)

1987 ◽  
Vol 42 (4) ◽  
pp. 489-494 ◽  
Author(s):  
Eckehard V. Dehmlow ◽  
Roland Kramer
Keyword(s):  
Thermal Stability ◽  
Gas Phase ◽  
Condensed Phase ◽  
Secondary Products ◽  
Gas Phase Reactions ◽  
Stereoselective Reduction ◽  
Derivatives Of ◽  
Thermal Stability Of

Abstract The title compounds la-3c were prepared by stereoselective reduction of the respective dibromides. Pyrolysis gave allylic bromides (8, 9, 11) as primary and dienes (10, 12) as secondary products. Product ratios were independent of the stereochemistry of the starting materials. No differences of the rearrangement rates of the stereoisomers were observed in gas phase reactions of the derivatives of bicyclo[6.1.0]- and bicyclo[8.1.0]alkanes. With the larger bicyclo[10.1.0] derivatives, however, distinct differences in the thermal stability of cis-trans-isomers4c/5c or 2c/3c were found in condensed phase.

scholarly journals The extracellular matrix of Volvox carteri: molecular structure of the cellular compartment.

1989 ◽  
Vol 109 (6) ◽  
pp. 3493-3501 ◽  
Author(s):  
H Ertl ◽  
R Mengele ◽  
S Wenzl ◽  
J Engel ◽  
M Sumper
Keyword(s):  
Extracellular Matrix ◽  
Chemical Structure ◽  
Chemical Nature ◽  
Sulfated Polysaccharide ◽  
Surface Glycoprotein ◽  
Amino Acid Residues ◽  
Volvox Carteri ◽  
Cellular Compartment ◽  
Cross Links ◽  
Cellular Compartments

The extracellular matrix (ECM) of Volvox contains insoluble fibrous layers that surround individual cells at a distance to form contiguous cellular compartments. Using immunological techniques, we identified a sulfated surface glycoprotein (SSG 185) as the monomeric precursor of this substructure within the ECM. The primary structure of the SSG 185 poly-peptide chain has been derived from cDNA and genomic DNA. A central domain of the protein, 80 amino acid residues long, consists almost exclusively of hydroxyproline residues. The chemical structure of the highly sulfated polysaccharide covalently attached to SSG 185 has been determined by permethylation analysis. As revealed by EM, SSG 185 is a rod-shaped molecule with a 21-nm-long polysaccharide strand protruding from its central region. The chemical nature of the cross-links between SSG 185 monomers is discussed.

Thermal Stability as a Function of Chemical Structure.

1961 ◽  
Vol 6 (1) ◽  
pp. 87-98 ◽  
Author(s):  
E.S. Blake ◽  
W.C. Hammann ◽  
James W. Edwards ◽  
T.E. Reichard ◽  
M. R. Ort
Keyword(s):  
Thermal Stability ◽  
Chemical Structure

Synthesis of biomass based plasticizer from linoleic acid and cardanol for preparing durable PVC material

2021 ◽  
Author(s):  
Hongying Chu ◽  
Huabei Li ◽  
Xiaoyan Sun ◽  
Yaowang Zhang
Keyword(s):  
Thermal Stability ◽  
Linoleic Acid ◽  
Chemical Structure ◽  
Dioctyl Phthalate ◽  
H Nmr ◽  
Plasticized Pvc ◽  
Migration Resistance ◽  
Ft Ir ◽  
And Migration ◽  
Thermal Stability Of

Abstract In this paper, we synthesized a kind of bio-based plasticizer epoxidized linoleic acid cardanol ester(ELCE) from cardanol and linoleic acid. Its chemical structure was characterized with FT-IR and 1H NMR. Polyvinyl chloride(PVC) blends plasticized with ELCE were prepared via thermoplastic blending with torque rheometer. The performance including torque, mechanical property, thermal stability, plasticizing property and migration resistance of plasticized PVC blends were investigated and compared with plasticized PVC blends with commercial plasticizer dioctyl phthalate(DOP). The results showed that ELCE improved thermal stability of PVC blends. ELCE played more excellent plasticizing effect on PVC blends than DOP. The better solvent extraction resistance and volatile resistance of ELCE make it impossible to completely replace DOP in PVC products.

Oxidative Polymerization of 3-Amino,2'-,(3')–Nitrodiphenylazomethin

2018 ◽  
Vol 935 ◽  
pp. 134-139 ◽  
Author(s):  
Timur A. Borukaev ◽  
A.Kh. Malamatov ◽  
M.K. Vindizheva ◽  
A.V. Orlov ◽  
S.G. Kiseleva
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chemical Structure ◽  
Oxidative Polymerization ◽  
Polymerization Process ◽  
Chain Growth ◽  
Polymer Product ◽  
Two Stages

Oxidative polymerization of 3-amino,2'-,(3')-nitrodiphenylazomethine was carried out in various ways. A possible mechanism for the polymerization of 3-amino,2'-,(3')- nitrodiphenylazomethine, where chain growth occurs as type N-C, is shown. It has been found that the yield of the polymer product is affected by the polymerization process and time. The chemical structure of the polymers obtained is established. The study of the thermal properties of polymers showed a low thermal stability and the process of destruction proceeds in two stages.

scholarly journals Thermodynamically stable [4 + 2] cycloadducts of lanthanum-encapsulated endohedral metallofullerenes

2014 ◽  
Vol 10 ◽  
pp. 714-721 ◽  
Author(s):  
Yuta Takano ◽  
Yuki Nagashima ◽  
M Ángeles Herranz ◽  
Nazario Martín ◽  
Takeshi Akasaka
Keyword(s):  
Thermal Stability ◽  
Material Science ◽  
Molecular Structures ◽  
Spectroscopic Methods ◽  
Dynamic Nmr ◽  
The Novel ◽  
Endohedral Metallofullerenes ◽  
Derivatives Of ◽  
Paramagnetic Properties

The [4 + 2] cycloaddition of o-quinodimethanes, generated in situ from the sultine 4,5-benzo-3,6-dihydro-1,2-oxathiin 2-oxide and its derivative, to La metal-encapsulated fullerenes, La2@C80 or La@C82, afforded the novel derivatives of endohedral metallofullerenes (3a,b, 4a,b and 5b). Molecular structures of the resulting compounds were elucidated using spectroscopic methods such as MALDI–TOF mass, optical absorption, and NMR spectroscopy. The [4 + 2] adducts of La2@C80 (3a,b, and 4a,b) and La@C82 (5b), respectively, retain diamagnetic and paramagnetic properties, as confirmed by EPR spectroscopy. Dynamic NMR measurements of 4a at various temperatures demonstrated the boat-to-boat inversions of the addend. In addition, 5b revealed remarkable thermal stability in comparison with the reported [4 + 2] cycloadduct of pentamethylcyclopentadiene and La@C82 (6). These findings demonstrate the utility of sultines to afford thermodynamically stable endohedral metallofullerene derivatives for the use in material science.

scholarly journals 3D Printed Chromophoric Sensors

Chemosensors ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 317
Author(s):  
Zachary Brounstein ◽  
Jarrod Ronquillo ◽  
Andrea Labouriau
Keyword(s):  
Thermal Stability ◽  
3D Printing ◽  
Material Properties ◽  
Chemical Structure ◽  
Elevated Temperatures ◽  
Advanced Manufacturing ◽  
Color Changes ◽  
Printed Sensors ◽  
3D Printed ◽  
Manufacturing Techniques

Eight chromophoric indicators are incorporated into Sylgard 184 to develop sensors that are fabricated either by traditional methods such as casting or by more advanced manufacturing techniques such as 3D printing. The sensors exhibit specific color changes when exposed to acidic species, basic species, or elevated temperatures. Additionally, material properties are investigated to assess the chemical structure, Shore A Hardness, and thermal stability. Comparisons between the casted and 3D printed sensors show that the sensing devices fabricated with the advanced manufacturing technique are more efficient because the color changes are more easily detected.

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